Thank you for viewing. All carbon, and the AT spring is a medium gold spring. Of course, it's okay for official races. It's made so that you can just attach it, such as countersunk screw processing, slide damper processing, and 3mm hole expansion processing. It's hard to see in the photos, but the slide damper is independent. 《Gimmick Features》 The slide damper absorbs impact in corners and allows for smooth turning. The brake stay has been countersunk. The multi-wide carbon rear stay has not been countersunk to apply thrust to the rollers. Due to individual customizations, it may not be possible to install, so we do not guarantee that it can be installed. Since it is made as a personal hobby, there may be some scratches, so please refrain from purchasing if you are sensitive to such things. ※The seller on Amazon and Yahoo Shopping is selling without stock, so if you buy it, you will get a fake. 70 #ruupapa's other products